Uncommon Descent Serving The Intelligent Design Community

Evolution vs common descent, universal common descent


There is a fair bit of confusion out there around three terms:

1. Evolution

2. Common descent

3. Universal common descent

The recent announcement of a rethink evolution conference sponsored by the Royal Society in London in November has meant that many people now know about the growing problems with the textbook Darwinism we learned in school.

But confusion among terms can turn productive discussions into shouting matches. Here are some conversation pointers that I have found helpful:

1. Evolution: Life forms can alter greatly over generations, and in many cases permanently.

At one time, Darwinism (natural selection acting on random mutation) was the default explanation of evolution (often functioning in place of a plausible explanation). That theory, credited to Charles Darwin, attributes evolution to small, accumulated random changes that happen to confer a survival advantage on a life form. The life form then passes on these altered genes. Over time, the accumulated small, possibly reversible, changes become big, irreversible ones.

The advantage of Darwinism is that it is easy to understand and assimilate into popular culture, including art, literature, and pop psychology . The disadvantage is that it has been hard to document as a fact. Even iconic examples like the supposed evolution of the beaks of Darwin’s finches have turned out not to be permanent changes.

More significantly, in recent decades, we have learned about a number of ways evolution can happen: convergence on a common goal, horizontal gene transfer,  epigenetics, devolution, self-organization, genome doubling, hybridization, jumping genes, and symbiosis.

In other words evolution happens*, but not usually the way the evolution experts have said.

Meanwhile, within Darwinism, fierce controversies rage about natural selection vs. group selection, and what role sexual selection (mate choice) plays.

Clearly it’s time to start listening to the fossils again.

* If a person believes that life forms cannot, in principle, change permanently over generations, then the onus is on them to explain why they know that can’t happen.

2. Common descent:A given life form goes back through a very long line of ancestors to an earlier, perhaps simpler life form. That seems eminently reasonable in principle, but the family tree has often proven difficult to reconstruct. The molecular clock, as it is called, is often a poor fit with the fossil record. And convergence of different life forms on the same strategies produces many surprises.

The truth is, we don’t know very much yet. Sometimes the argument for common descent amounts to “Believe it because it is Science! After all, things couldn’t have happened any other way except by Divine Intervention!” Which is why I like to avoid arguments about common descent as a dogma of some kind, and concentrate on specific situations for which we have reliable information.

3. Universal Common Descent (UCD): All life originated in a single cell that accidentally came together billions of years ago in the ocean. That belief is simply an article of faith. We don’t know and probably don’t even have a way of knowing. Prominent figures like Carl Woeseand Craig Venter, for example, don’t think the evidence shows that all life descends from a single cell.

In any event, we now find ourselves in the origin of life (OOL) controversy, where things are much murkier than in most chapters of the history of life to date. There are so many competing schools of thought on OOL that dogmatism is, among other things, a social sin.

I have found that taking the time to outline the issues in this way helps circumvent Darwin bullies. They take control of a conversation to announce that they have the answer, others don’t know anything, those who disagree have unworthy motives, Darwin has triumphed over God, Jesus loves Darwin and so should you, etc., etc.

They got away with that stuff for decades, but now they may as well be saying:

My name is Used-to-was,

I am also called Played-out and Done-to-death,

And It-will-wash-no-more.


Note: News posting light until later this evening, due to O’Leary for News’ current alternate day job.

See also: What we know and don’t know, about the origin of life

By the way Denton has a new book. Has anyone reviewed it here? jerry
The situation is worse for the icons that supposedly gave evidence to Darwinism now. Darwin's finches have flown the coop, and now serve another master that you mentioned. Epigenetics. http://gbe.oxfordjournals.org/content/6/8/1972.full Yarrgonaut
Evolution did happen. peoples looks changed greatly relative to Noahs family according to the bible and YEC. The bible recognized people became black who before were not. stressed it in a passage. I say marine mammals were land lovers first and only evolved after the flood and into empty seas of previous monsters. marsupials, I insist, were placentals first and only changed upon migration and many other orders. All snakes came from one pair off the ark but today spitters and squeezers are everywhere. Indeed few creatures today would of been seen on creation week or on the ark. Change in body plans is as real and true as can be. its about mechanism and timelines that is the issue for many. So yes to common descent for many but not to Darwin's ideas. As people get smarter they will reject the impossible claims that fish became fishermen in big boots. This is happening in our time. Old Chuck had some good observations and ideas but his great conclusion was plain upper class Anglican English victorian WRONG!! Robert Byers
More significantly, in recent decades, we have learned about a number of ways evolution can happen: convergence on a common goal, horizontal gene transfer, epigenetics, devolution, self-organization, genome doubling, hybridization, jumping genes, and symbiosis.
I don't suppose you could explain how any of these are opposed to "Darwinism"? In the narrow-sense (i.e. relating to selective advantage) drift (not mentioned) and perhaps self-organisation are not Darwinian. Trans-generational eipgenetics is different than Darwinism, but it's hard to see how it can be an important evolutionary process (since the reason to be interested in such changes is how labile they are). wd400
Lee Spetner at 1: Popular culture makes quite clear that pop atheism is the message both sent and received. The science part is optional, and easily tweaked, jettisoned, redesigned, or marketed under a different name. After about a decade and a half on this beat, the thing that stands out for me is how much of the current scene depends on the social impact of - Darwin's trolls cursing at Web sites - Darwin-in-the-schools lobbies descending on school boards, and - ignorant "concern bimbos" gushing on Airhead TV. But the biggest surprise for me was that so few science journalists sensed the ground moving under our feet. I know of five, three of whom got scared and left. Suzan Mazur, an American freelancer, had everything to gain and nothing to lose by staying with the story. An extra little surprise was how Darwin's boys, who probably think of themselves as very enlightened folk, thought nothing of making disparaging sexist remarks about Mazur. Here, for example. To them, I say: Guys, you need longer pants. Your trotters are showing. News
Evolution and common descent If evolution is defined as simply the change in living organisms over time, then it could not serve as a theoretical support for atheism or materialism. It would then not stand in opposition to divine creation. If this were all there were in the concept of evolution, there would be no intimidation from the atheist-materialist class to convert the misguided souls who think various life forms were separately created. But there is a great deal of intimidation in academia. So there must be more to what is meant by evolution. Judging from the propaganda coming from the evolutionary establishment, “evolution” must include that life’s origin and development was purely natural, which has to mean life happened by chance. (Of course life’s origin is not part of evolution, but it is included in the party line.) Moreover, “evolution” has to include common descent because we are constantly reminded that we have evolved from slime mold. In summary, the way evolution is marketed by the establishment implies that common descent is included in evolution. Lee Spetner

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